Egress 4-bar hinge assembly

Abstract

An egress 4-bar hinge assembly having two load-bearing links that pivot about spaced-apart bearing pivot points, wherein an entire length of at least one of the links overlies a planar bearing surface. The two links include a cooperating interface selected to engage through only a portion of the respective range of motions. The hinge assembly includes a support extension to define the bearing surface, wherein the support extension can include an integral end cap.

1. A hinge assembly comprising:
 (a) an elongate track having a length and a width; 
 (b) a support extension fixedly connected to the track and extending beyond the length of the track, the support extension having an integral planar bearing surface and an end cap extending transverse to the bearing surface; 
 (c) a first link pivotally connected to the support extension beyond the length of the track at a first pivot point, the first link movable between a closed position and an open position, the first link having a given length, and the bearing surface underlying at least a portion of the given length of the first link in the closed position; 
 (d) a second link pivotally attached to the support extension beyond the length of the track at a second pivot point spaced apart from the first pivot point to locate the first pivot point intermediate the second pivot point and the end cap, the second link movable between a closed position and an open position, the bearing surface underlying at least a portion of a length of the second link in the closed position; 
 (e) a shoe slidably engaging the track; 
 (f) a sash bar pivotally attached to the first link; and 
 (g) a strut pivotally attached to the sash bar, the second link and the shoe. 
 
   
   
     2. The hinge assembly of  claim 1 , wherein the bearing surface underlies a sufficient length of the second link in the closed position to preclude detrimental deflection under an operating load. 
   
   
     3. The hinge assembly of  claim 1 , wherein the track is formed of a first metal and the support extension is formed of a different second metal. 
   
   
     4. The hinge assembly of  claim 1 , wherein the first link and the second link include cooperating features to define an engagement through a limited range of motion between the open position and the closed position. 
   
   
     5. A hinge assembly comprising:
 (a) a track having a length and a width; 
 (b) a support extension attached to the track, the support extension having a planar bearing surface; 
 (c) a first link pivotally attached to the support extension at a first pivot point, the first link movable between the closed position and an open position, the first link having a given length, and the bearing surface underlying the given length of the first link in the closed position; 
 (d) a second link pivotally attached to the support extension at a second pivot point spaced apart from the first pivot point, the second link movable between a closed position and an open position, the bearing surface underlying at least a portion of a length of the second link in the closed position; 
 (e) a shoe slidably engaging the track; 
 (f) a sash bar pivotally attached to the first link; 
 (g) a strut pivotally attached to the sash bar, the second link and to the shoe and 
 (h) a tab in one of the first and second length being engageable with a capture recess in the other of the first and second links for transferring a limited range of angular motion between the first and second links, 
 wherein the tab and capture recess are shaped to accommodate unequal angular velocities of the first and second links about the first and second pivot points, and 
 wherein the support extension includes an integral end cap that is connected to the support extension beyond the length of the track. 
 
   
   
     6. The hinge assembly of  claim 5 , wherein the first link and the second link in the open position dispose the sash bar generally perpendicular a longitudinal dimension of the track. 
   
   
     7. The hinge assembly of  claim 5 , wherein the first link includes one of a tab and a capture recess and the second link includes a remaining one of the tab and the capture recess. 
   
   
     8. The hinge assembly of  claim 7 , wherein the tab and the capture recess are sized to profitably engage through only a portion of motion between the open position and the closed position of the first and second links. 
   
   
     9. A hinge assembly comprising:
 (a) a track having a width; 
 (b) a support extension attached to the track, the support extension having a planar bearing surface; 
 (c) a first link pivotally attached to the support extension at a first pivot point, the first link movable between the closed position and an open position, the first link having a given length, and the bearing surface underlying the given length of the first link in the closed position; 
 (d) a second link pivotally attached to the support extension at a second pivot point spaced apart from the first pivot point the second link movable between a closed position and an open position, the bearing surface underlying a length of the second link in the closed position; 
 (e) a shoe slidably engaging the track; 
 (f) a sash bar pivotally attached to the first link; and 
 (g) a strut pivotally attached to the sash bar, the second link and to the shoe, 
 wherein the support extension is an integral monolithic piece. 
 
   
   
     10. The hinge assembly of  claim 5 , wherein the support extension includes at least two apertures, a first of the two apertures in the support extension located beyond a length of the track for fastening the extended portion to a window frame and a second of the two apertures in extended portion being aligned with an aperture in the track for fastening the extended portion to the track and to the window frame. 
   
   
     11. The hinge assembly of  claim 5 , further comprising an end cap integrally formed with the support extension, the end cap having a collection surface described by a curve with a continually varying first derivative. 
   
   
     12. The hinge assembly of  claim 5 , wherein the first and second links including contacting surfaces that engage each other to form a stop to limit movement of the hinge assembly beyond a predetermined open configuration. 
   
   
     13. A hinge assembly comprising:
 (a) a track having a width; 
 (b) a support extension attached to the track, the support extension having a planar bearing surface; 
 (c) a first link pivotally attached to the support extension at a first pivot point, the first link movable between the closed position and an open position, the first link having a given length, and the bearing surface underlying the given length of the first link in the closed position; 
 (d) a second link pivotally attached to the support extension at a second pivot point spaced apart from the first pivot point, the second link movable between a closed position and an open position, the bearing surface underlying a length of the second link in the closed position; 
 (e) a shoe slidably engaging the track; 
 (f) a sash bar pivotally attached to the first link; and 
 (g) a strut pivotally attached to the sash bar, the second link and to the shoe, 
 wherein the support extension has a longitudinal centerline, and a dimension of the end cap along the longitudinal direction increases with an increasing distance from the centerline. 
 
   
   
     14. A hinge assembly comprising:
 (a) a track having a width; 
 (b) a support extension attached to the track, the support extension having a planar bearing surface; 
 (c) a first link pivotally attached to the support extension at a first pivot point, the first link movable between a closed position and an open position; 
 (d) a second link pivotally attached to the support extension at a second pivot point spaced apart from the first pivot point, the second link movable between a closed position and an open position, the first and second links having given lengths, and the bearing surface sized to underlie at least one-half of the given length of one of the first link and the second link in the closed position of the first link and the second link; 
 (e) a shoe slidably engaging the track; 
 (f) a sash bar pivotally attached to the first link; and 
 (g) a strut having pivotal attachments to the sash bar, to the second link and to the shoe. 
 
   
   
     15. The hinge assembly of  claim 14  in which the bearing surface of the extended portion underlies at least one-half of the given length of the second link.